A new temporary skimmer antenna has been installed at the SE0X skimmer site. I didn’t expect much from the small and simple PA0RDT active mini-whip antenna, but its good performance, especially on 160 meter, surprised me in the ARRL DX contest.

The old trusty Clifton active antenna broke down recently and I had to find a replacement in time for the ARRL DX contest as I planned to enter the unlimited category.

Quite some time ago I bough the PA0RDT mini whip antenna kit from OK2ZI on Ebay. Then my plan was to have it as a small and handy antenna to test SDR receivers on the bench, but now it became my back-up solution to get the SE0X skimmer back on air in time for the contest.

The mini-whip circuit board was placed in a plastic enclosure and was installed the weekend before the contest at the SE0X off site skimmer location. At the time I though the Clifton 11 dB preamp would be enough, but listening to the RX over the week I decided it needed more gain. Unfortunately work got in the way of replacing the preamp, so it had to be done in the middle of the contest weekend.

On Saturday February 16 around 14:00 UTC the preamp was replaced with a W7IUV type preamp and a LBS common mode choke was added on the incoming coax. This turned out to make a big difference, especially on 160 meter!

The upper table below compare the number of spots by several different SM skimmers on the 160 meter band during Saturday from midnight to 14:00 UTC. The lower table show the the same time period on Sunday.

It’s true that propagation on 160 meter was better on Sunday morning which is demonstrated by the fact that all skimmers are showing a substantially higher amount of NA spots on Sunday compared to Saturday. The average increase of the other skimmers (not including SE0X Skimmer) where 84% which is a lot. But the increase of spots at SE0X was enormous compared to the anyone of the other skimmers.

It is worth mentioning that the antenna needs to be placed away from the electrical fields in building, power lines etc. The SE0X skimmer is place 75 meters away from the closest building to ensure a quiet surrounding. The PA0RDT mini-whip will not work in or too close to buildings.

Calling the antenna “mini-whip” is a little misleading, the whip is a pice of copper on the printed circuit board creating the required capacitance.

The conclusion is that with the PA0RDT mini-whip antenna is a low cost alternative to more expensive active antennas for a skimmer receiver or for receiving weaker signals on lower bands. It does benefit from a common mode choke and around 20 dB gain from a preamp.

]]>http://se0x.info/?feed=rss2&p=34860QRP Record Hunting in CQ-160 CWhttp://se0x.info/?p=3501
http://se0x.info/?p=3501#respondMon, 18 Feb 2019 22:32:56 +0000http://se0x.info/?p=3501Read more ›]]>Shame on me! I haven’t updated the blog in a while, so here we go. I have several soap box notes prepared from the major contests this season. Lets start with CQ-160 CW.

The goal in CQ160 CW this year was to break the SM record in the QRP class. I also wanted to work at least a few states which I figured should be doable if propagation was decent. Unfortunately it wasn’t, propagation was not good enough and only marginal signals came across from NA. But for breaking the record it didn’t matter much as there was plenty of EU stations around to support the effort.

The record broke already before 6:30 on Saturday morning, at 19:00 my own score goal was achieved. At this point I decided to adjust the goal for the weekend to 500 contacts.

I did work a few AF and AS DX multipliers; 4X, 5B, CT3, EA8, HZ, UA9 and UN. Topband was not broken, it wasn’t just supportive enough to let 5 watt make the trip to NA.

Because of the weather I couldn’t reach the station so the contest was operated remote using the K3-K3/0 combo. Transmit antenna is the newly installed Axtorp linear loaded vertical from Lannabo Antennas over my experimental floating ground rods. I’ll have more on this new antenna and the floating ground rods in an upcoming post.

I am happy with the results. The choice of entering in the QRP category was the right one, trying to top my previous efforts in a High Power category had been just frustrating with the weak band conditions.

When the finish line was passed I had more than 500 contacts logged. Some of these where dupes, and the number of contacts added up at 487 uniques. The total numbers of multipliers collected was 47. Final claimed score 115103.

As of Today, November 1st 2018, the maximum power allowed for Swedish amateur radio operators have been lowered to a maximum of 200 watt PEP. This is a change in regulations by the Swedish PTS, Post and Telecommunication authority. The reason given is that it is done to harmonise with the new spectrum plan. There have been no reports of interference relating to amateur radio activity reported to PTS.

Amateur radio operators can apply for a permit to use higher power levels. PTS will hand out permits for the old power level of 1kW in exchange for a fee. This permit is only valid for the locations specified in the application As this licence is given according to general communications regulations one wonders if higher power levels now are possible.

At this time, November 1st, around 400 hams have sent in their application for using high power.

Update October 31st: SM0MDG has been granted 1000 watt PEP permit for the SE0X contest station. An application to use 1500 watt was turned down by the PTS.

2018 has been a rather slow year at SE0X with limited activity due to family and work commitments. Therefor it feels great that the few efforts are paying off! The results of CQ-160 and CQ-WPX brought the excitement levels up right in time for the contest season.

In CQ-160 CW this winter the objective was to break the Single Operator Low Power SM record. Right before the contest a winter storm almost broke the TX vertical. After a rescue effort the vertical was standing straight up again, well almost straight. Was the record broken? Read the full report here.

This year we made another attempt to beat the MULTI-OP SM record in CQ-160 SSB. SM0MDG and SM0MLZ worked the contest remote as the station was not accessible due to current weather conditions. Filters and patience was crucial to survive the QRM. But was it enough to break the record? Read the full report here.

In March it was once again time for CQ-WPX, but unlike previous year’s multi operator efforts. 2018 was the first year in a long time that SE0X competed in a single operator category, SINGLE OPERATOR ASSISTED LOW POWER ALL BAND. Was another record broken in this competitive contest? Yes, it was and I am proud the SM record was broken. Check the SE0X awards wall for this and many other awards earned over the years.

Finally, a very nice plaque sponsored by SM3EVR for the best combined CW+SSB score in the Scandinavian Activity Contest will decorate the operating position at SE0X his weekend in the SAC CW Contest. See the plaque here.

As the 2018 IARU HF Championship was chosen as the arena for WRTC activity was high this summer contest weekend. I decided to kick out the K3/TS-590 combo and go all SDR in SO2R configuration. Propagation was also helpful, especially on low bands. Read the full writeup of the IARU HF Championship weekend at SE0X here.

I decided to play with technology and therefore entered in SO Unlimited. SE0X was wired up for semi-SO2R using the SunSDR2 PRO SDR transceiver as radio 1 plus a ColibriNANO SDR receiver as radio 2. Using the clever SDC utility from Yuri UT4LW allowed med to skim both receivers for spots and then combine these local spots with skimmer spots from our offsite skimmer. All spots where sent to N1MM and spots gathered by each radio where also displayed on that radio’s spectrum display.

Both radios had hardware controllers but as radio 2 couldn’t transmit ALT-F5 in N1MM was used to swap radios to be able to transmit on Radio 2’s frequency. Not the most elegant solution, but the second radio was useful for sweeping other bands for multipliers. A microHAM u2R was used for SO2R switching and 5B4AGN band pass filters kept the ColibriNANO’s RX reasonably free from interference.

A powerful feature of the small ColibriNANO is the automatic attenuator. At times the RF levels became overwhelming for this tiny direct sampling SDR. When this happened the automatic attenuator adjusted itself to an attenuation level so that clipping would be avoided.

I had planned to use a SPE 1.3-FA amplifier to be able to get full power with the low output drive level of the SunSDR2 PRO. For different reasons this plan failed, so I went to plan B using my old 1k-FA only able to produce about 500 watts on 20-10 meter and 700 watts on 40 and 80 meter with the 15 watt drive level from the transceiver.

Even if higher bands where not in their best shape, propagation was good enough to maintain action on 20 meter. 15 meter also provided contacts and multipliers and even 10 meter came to life with some DX including multipliers from zone 43 and 44. 40 meter was strong overnight with some NA stations peaking 20-30 dB over S9 which made the share of NA stations on 40 equal to the share on 20. 80 meter was also OK, but with less DX. Unfortunately, the 160 meter antenna was not available so a few multipliers was not within reach for me.

I operated quite casually spending some time to work Y8 WRTC stations and collect some of the DX mults. I took breaks for dinner and breakfast and even got 45 minutes of horizontal recharge overnight. The total calculated operating time was a bit over 22 hours.

I am quite happy with the result. The all-SDR setup worked very well but also spiked ideas for how to improve the ergonomic layout of the station when permamnetly replacing the K3/TS-590 combo with the SunSDR2 PRO radios. The claimed score is decent and breaks the record in the unlimited/assisted category, but it is about 300k short of SE0X’s 2014 record in the unassisted category.

Rewiring the station for IARU HF Championship. This year I am going to enter the Single Operator Unlimited CW High Power category with the goal so set a decent record. The station will be using only SDR, Software Defined Radio equipment, and at this moment preparation is in full force.

The station will be using one SunSDR2 PRO transceiver as Radio 1 and one ColibriNANO SDR direct sampling receiver as Radio 2 in SO2R configuration. As Radio 2 is only RX N1MM’s swap functionality will be used a lot.

SDC, Software Defined Connectors will be used to skim both radio’s sampled passbands and combined these spots with SE0X skimmer spots and cluster spots from other sources.

A fully automatic SPE amplifier will provide the High Power output and 5B4AGN band pass filters will keep RX for the listening radio clean.

This morning a nice surprise appeared in the mail. It seems like I had the highest combined CW + SSB score in SOAB HP Unassisted in the Scandinavian Activity Contest (SAC). Not an official category, but very nice plack för the wall. Thanks to the sponsor SM3EVR Tord Julander!

The full information about the SAC contest and the score database can be found here.

CQ160 SSB is one of the most challenging phone contests. With thousands of operators sharing the narrow 160 meter band good filters and a lot of patience is crucial to survive this weekend while producing a respectable score. SM0MDG and SM0MLZ teamed up and logged on via remote to SE0X with the goal of breaking the Multi Operator SM record from 1995. How did it go? Read on to find out. Our goal for CQ160 SSB was to break the SM Multi-OP record from 1995 by 7S3OWG. We made an attempt at the same goal in 2016 but ended up just a notch below. So now this was our second attempt.

Right from the start the propagation was weak. The most used antenna this year was our south pointing BOG which is a clear hint that EU dominate the log. There was very little DX, and only a few of the biggest NA stations where logged in Saturday sunrise.

Second night was even worse, On Sunday morning’s sunrise the only NA coming through was VY2ZM. Jeff was loud as always, it seems bad propagation to PEI is non-existent. The rest of Sunday was pretty slow as usual with mostly grey spots in the band map. The occasional Sunday surprise multiplier saved the day, and the SM record where passed 3 hours before the end of the contest.

The contest was worked from remote as SE0X was not accessible due to current weather conditions. SM0MDG used a K3/0 to connect to the K3 at SE0X and SM0MLZ used a K3/100 as the remote head. The Remoterig remote control setup worked very flawlessly as usual.

To avoid the annoyance of loosing focus on the log window when switching RX antennas “Flic” bottons where installed, one for switching between three RX antennas, and a second one controlling a vacuum relay that change tap on the vertical loading coil to extend the bandwidth of the TX antenna. A Flic button is a self adhesive pushbutton that connects via bluetooth to a smart phone app. Using the Flic app a variety of actions can be defined when pressing the button, including http calls which we use for switching RX antennas. Each button can accept three command; single click, double click and click-and-hold. The biggest upside is the easy of use once configured, the downside is that sometime the response time can be a little longer than using the switch web interface directly. And of course it relies on the smartphone being charged and connected the internet.

Equipment:

K3 + SPE 1k, about 900 watts

N/E + N/W Pennants + South BOG

Clifton Labs active vertical for diversity RX

Remoterig

How did it go? This time we were more lucky finishing at 168.504 claimed points, a few thousands above the record. Now we cross our finger and wait for the result. Lets hope we got most of it right, quite a few contacts were marginal in the QRM.

UPDATE: The SM record was officially broken and the award can be found on our awards wall.

Thanks to everyone who worked us, we certainly needed every point this year!

The 2018 edition of the CQ160 CW provided lots of fun and SE0X broke the SM Record from 2004 in the Single Operator Low Power category. But right before the contest it looked like we had to cancel because of antenna problems. Full story follows, keep reading.

I arrived at the station just before lunch on Friday. In a addition to the recent problems keeping the vertical straight up in the winter storms, both Pennant RX antennas had been torn apart by the brute force of nature. So before even getting lunch I was engaged in antenna work. And being alone at the station, most part of the daylight hours where spent outdoors maintaining the vertical and repairing pennants.

When sunset came preparations continued indoors. I rewired the station for the contest and updated the software. I also added a pan-adapter to the K3 for the visual advantage in a crowded band. I used a ColibriNANO, a small direct sampling USB SDR receiver and synchronised it with the K3 using SDC, Software Defined Connectors, developed by UT4LW. The SDR shared receiving antennas with the K3 through a divider. To protect the receiver the RX antenna was automatically disconnected during transmit. This arrangement worked pretty well and the addition of the panadapter really made a difference. The screenshot show what the band looked like right after sunset on Saturday. Pretty crowded alright!

Propagation was good the first morning, but it was quite hard to cut trough to NA, I suppose they had lots of QRM on their side. Second morning started OK to NA, but then it slowed down and the boost at sunrise was minimal. Topband was extremely crowded when EU was awake, sometimes it was almost impossible to find a run frequency in the crowded band. I wonder if the number of submitted CQ-160 logs will increase this year too. In 2017 the number of logs submitted was 2661compared to 2112 in 2016, an increase of 549 logs! In the past 15 years CQ160 CW have almost tripled in size, 2002 the submitted number of logs were only 902.

The top photo of the PC screen shows the point where the SM record was broken, W2GD came in a the right moment and pushed me over the line with a nice multiplier. The record was set by 7S7V fourteen years ago, and my goal to break it was achieved with several hours left to go.

Other memorable contacts include W1UE Dennis, a SE0X team mate a few years ago in CQWPX SSB was one of the few NA stations to find and log me. Another one was Guy K2AV who now is logged using the FCP, Folded Counter Poise, he offered me advice on few months ago. A last minute surprise where also offered in the form of an ATNO, Kosovo Z60A, that was found during a S&P session. And when I had finally given up on the JA multipler JH2FXK checked into my log with a big signal.

Equipment used

Elecraft K3

SPE 1k-FA amp, used to to get 150 watt and extend the antenna bandwith using the tuner

ColibriNANO direct sampling SDR in a USB stick used as pan-adapter

N/E + N/W Pennants + BOG pointing south (shared between K3 and ColibriNANO using a divider)

Clifton active vertical as diversity antenna for K3

So to summarise; CQ160 CW 2018 was a fun event. A little shaky because of the recent problems with the vertical, but the antenna stood up to the challenge. Propagation was fair to good and the mood was on top. With resonable effort the goal was achieved and the record was broken. Now we just wait for the results to be published.

UPDATE: The SM record was officially broken and the award can be found on our awards wall.

After years of successfully keeping my Topband vertical in service during winter storms in costal environment my streak of luck has finally come to an end. This season alone I had more problems with the Topband vertical than in the past 10 years. Heres a quick recap of the so far very eventful season at SE0X.

November: Vertical comes down in a storm. A few days later we raised it up again, but the FCP and loading coil where destroyed when the vertical landed on top of those. We were able to force the pipes pretty straight with guy line tension. Stew Perry cancelled.

January 13: Loading coil and FCP replaced. Antenna back in service!

January 15: Another storm hits the area, measure loads of SWR via remote after the storm.

January 19: Quick visit to SE0X, the antenna is bent 90 degrees. I am able to raise it up, but now it is severely deformed.

January 23: Gail force wind in the area, remotely I measure 6:1 SWR. No no no, not again! Starting to look for alternative stations to work CQ160 from.

January 25: SWR back to normal, the antenna apparently raised itself up again and works well as soon as the wind settled. Logged JT and a few others. Hope is back, maybe the CQ160 is happening after all.

January 26 (today): Back at the station. One of the top guys have slack. Antenna looks sad, but at least it is standing up. More adjusting of guy lines to make it reasonably straight.

WX forecast for the weekend looks good with only moderate winds from S/W which is favourable. Now I can just cross my fingers that the vertical will survive CQ-160 so we can aim for another record.

And if I am really lucky it might even be around for 3Y0Z, that would be the real bonus.

So if you hear me in CQ160 CW this weekend, work me quickly. You never know when its time for another diary entry in this never ending story of challenges.